The present disclosure relates to a display device and a display method, and particularly relates to a display device and a display method capable of displaying plural viewpoint images.
In recent years, a naked-eye 3D display device (hereinafter, referred to as a display device) capable of viewing 3D video images by guiding light of viewpoint images different from each other to right and left eyes is becoming popular. The display device guides light of given viewpoint images in plural viewpoint images to the eyeballs of an observer by using a parallax barrier or lenticular lenses. In a display device 90 shown in FIG. 8, light of viewpoint images of viewpoints 5 and 6 in light rays transmitting through transmitting portions 905a of a parallax barrier 905 is guided to the left eye and the right eye of an observer respectively, which enables stereoscopic vision of an image.
In respective pixels on a display screen of a display unit 900, respective viewpoint images are cyclically arranged. Therefore, at a boundary point of respective cycles (for example, between a viewpoint 6 and a viewpoint 1 in the case of 6-viewpoints), a pseudoscopic phenomenon occurs, in which light of a viewpoint image which should enter the right eye is guided to the left eye, and light of a viewpoint image which should enter the left eye is guided to the right eye. In a pseudoscopic area, the observer perceives a video image in which the near side and the far side of a 3D image are inverted, or views a video image with a sense of discomfort in which these are fused unnaturally.
It is difficult to fundamentally solve the problem of the pseudoscopic phenomenon as it occurs based on the principle in naked-eye display devices. Accordingly, a technique of controlling a position of the observer so as not to enter the pseudoscopic area by detecting a position of the observer's face has been proposed. For example, in JP-A-2004-282217 (Patent Document 1) and JP-A-7-038926 (Patent Document 2), there is proposed a display method of switching display positions of multi-viewpoint images continuously so that the observer is not positioned in the pseudoscopic area when the observer is in the pseudoscopic area or comes close to the pseudoscopic area. For example, the viewpoint images of viewpoints 1 to 6 are displayed in the upper drawing in FIG. 8, whereas, the display positions of the multi-viewpoint images are switched from viewpoints 1 to 6→viewpoints 2 to 7→viewpoints 3 to 8 “continuously” so as to display viewpoint images of viewpoints 3 to 8 in the lower drawing, which allows the position of the observer in an orthoscopic area.